You might want to be more careful in checking your credit card statements for fraudulent charges. CSO notes that Amex has had to issue three breach notifications this month, due to three separate hacks.

Update: It looks like the data stolen also affects Visa, Mastercard, and Discover. Per CSO:

In all, [Anonymous] released 3,255,663 records from Visa; 1,778,749 records from MasterCard; 362,132 record from Discover; and 668,279 records from American Express. To date, only American Express has taken notification steps.

Also, 76,608 people in California should expect a data breach notification letter from Amex, thanks to their data being publicized by Anonymous Ukraine.

If you stayed at one of those hotels last year or shopped with one of those brands, check your statements more carefully and be on the lookout for any notices from your credit card. You might not be affected, but it's good to know what to do if your card is hacked anyway.